The goal of this proposal is to extend the histologic study of 300 prospectively collected human pancreases obtained at autopsy in order to evaluate the significance of focal abnormalities of acinar cell differentiation and growth. Such foci have been demonstrated to occur more commonly in human pancreas than has previously been appreciated. The morphologic features of some of these foci is strikingly similar to atypical acinar cell nodules described in pancreases of carcinogen-treated rats. The human pancreases will be classified according to the number of atypical foci present and the degree of acinar cell dysplasia which these foci exhibit, and also coded for the presence of hyperplastic and/or dysplastic changes in ductal epitheliym. The presence or absence of acinar cell and/or ductal cell abnormalities will be correlated with the pertinent clinical data including age, sex, race, occupation, smoking history and diabetes. The specific objective is to refine our understanding of the histogenesis of carcinoma of the exocrine pancreas in humans.